Note that the data published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution. For the most recent data, purchase the 2008 Report from Island Press.

The Indicator

The Data Gap

Data on nitrate concentration in groundwater need to be collected and reported in a consistent fashion across a broad and representative set of grassland and shrubland areas. Nitrate measurement is simple, straightforward, and largely unchanged since measurements began more than 100 years ago. Because many usable wells already exist, on both public and private lands, the cost of sampling and analysis is the primary factor limiting current efforts.

In addition, careful searching of federal, state, county, municipal, and private records could produce a valuable historical archive that would serve as a baseline against which to compare current conditions.

The technical note for indicators describing nitrate concentrations in forested, farmland, and urban/suburban areas provides information on the U.S. Geological Survey National Water Quality Assessment program, which is a potential future source of data for this indicator.

References

Nolan, B.T., and J.D. Stoner. 2000. Nutrients in groundwaters of the conterminous United States 1992-1995. Environmental Science and Technology 34:1156–1165.

Ramundo, R.A., C.M. Tate, and T.R. Seastedt. 1992. Effects of tallgrass prairie vegetation on the concentration and seasonality of nitrate-nitrogen in soil water and streams, pp. 9–12.

In D.D. Smith and C.A. Jacobs (eds.), Proceedings of the Twelfth North American Prairie Conference, Ames, Iowa. Smith, R.A., G.E. Schwarz, and R.B. Alexander. 1997. Regional interpretation of water quality monitoring data. Water Resources Research 33:2781–2798.

Tate, C.M. 1990. Patterns and controls of nitrogen in tallgrass prairie streams. Ecology 71: 2007–2018.